Vitreous enamel composition and method of making same



Patented Dec. 6, 1 927.

GEORGE McINTOSH SCOTT, OF LONDON, ENGLAND.

VITREOUS' ENAMEL COMPOSITION AND METHOD MAKING SAME.

No Drawing. Application filed September 24, 1925,

Serial No. 58,363, and in Great Britain October 22,

1924. Renewed July 16, 1926.

This'invention relates to vitreous enamel compositions and methods of making same. The composition is especially useful in producing designs upon vitreous surfaces by 5 the use of a, mesh stencil in applying the design. In reissue United States Letters Patent Number 16,048, reissued April 21, 1925, and granted to Herbert Hamilton Scott and George McIntosh Scott, there is described a method of producing such designs utilizing a pasty vitreous enamel composition containing finely ground vitreous enamel and an oily carrier, the composition being applied to the enamel surface by pressing the composition through a fine mesh stencil.

It was pointed out in said specification that it is important to have the composition in the form of a pasty consistency so that it would be deposited on the enamel surface, after passing through the mesh. in finely divided form, and that it must contain an oily vehicle to lubricate it to enible it to passthrough the fine mesh, and that the ingredients mixed with the ground frit or enamel should be of such a character that the composition will not dry out too rapidly, and that they may be readily volatilized without damage to the enamel o when the latter is fired.

The composition thus used as disclosed in said patent comprises enamel frit. a suitable coloring oxide, beeswax, turpentine, paraffin oil (kerosene), and a varnish such as lithovarnish which is composed largely or treated linseed oil.

The object of the present invention is toprovide an improved vitreous enamel composition which is particularly useful in, although in the broadest aspect of the inven tion, not limited to, the production of designs according to the process of said patent.

The invention consists'in the composition which is hereinafter described according to the preferred embodiment of the same, and in the novel features thereof, and in the process and novel features of the process of compounding or making the same.

I have found that such vitreous enamel compositions are improved by the use therein of an oily medium. that will liberate that, part of the kerosene which is in suspension in the composition. I have found that a suit-able mineral grease or 'jelly such as petroleum jelly-commonly known as vaseline-is well suited for this purpose; :and one aspect of the presentinvention comprises the use of such an oily medium in a vitreous enamel compound. I have further found that the ingredients of the composition embodying the present invention combine more readily; that the composition 7 able mineral oil such as paraffin oil in sufficient quantity to form a damp powder. and the latter is then worked up with a suitable mineral grease or jelly, such as petroleum jelly, to the desired pasty consistency suited to transmission through the meshes of the stencil. A quantity of tallow as hereinafter described may also be used with the vegetable and mineral oils. As will be understood, the combustible or carbonaceous matter burns away during the subsequent firing of the article after the design has been applied by means of the stencil, and it is therefore desirable to employ as little of the carbonaceous matter as possible in arriving at the desired pasty consistency of the composition, and to use ingredients which will effect the proper lubrication of the enamel composition through the meshes of the stencil consistent with maintaining a pasty consistency, and which can be volatilized with out endangering the enamel.

Inasmuch as the petroleum jelly causes some of the parafiin oil to separate out from the pasty mass after standing, I find .it advantageous in the case of such separation to remove the freed araflin oil, and restore the mass to the desired pasty consistency by means of more petroleum jelly.

In order that the invention may be clearly understood and readily carried into effect, I will now describe in further detail a com position iving satisfactory results and a method 0% compounding the same.

I take about thirty parts by weight of paraflin oil and three parts by weight of tallow to one part by weight of oxidized linseed oil and mix them by stirring at a temperature sufficient to melt the tallow and I then add the ground frit or quartz-like material and mineral coloring matter until a damp powdery mass is obtained and then work up the same to the desired greasy psfity consistency by means of petroleum J 11 i place of ordinary linseed oil I may use a somewhat thickened grade or modified form or substitute such for example as lithovarnish, in which case the tallow may be omitted and the amount of lithovarnish increased. In either case I find it advantageous to use the petroleum jell in two stages, the pasty mass first formed being allowed to stand for a few days to allow the jelly to cause some of the parafiin oil to separate out, whereupon this excess is drained off from the top of the mass and the latter is again worked up to the desired pasty consistency by means of more petroleum jelly. It will be understood, of course, that instead of using the oils or jelly or grease above described, suitable compositions containing same may be substituted so long as these compositions did not contain matter which interferes with the lubrication of the composition through the mesh of the sten oil, or with the roper volatilization of the roducts from t e enamel when the latter 1s fired, in a manner not to damage the enamel; and I wish to be understood in the" appended claims by reference to such in edients to include not only such ingreients but any suitable compositions containing the same.

While I have described my invention in detail with respect to one particular example of the composition embodying the invention which gives satisfactory results, and to the preferred method of compounding same, it will be understood by those skilled in the art, after understanding my invention, that various changes and modifications may be made without departing from the spirit or sco e of the invention, and I aim in the appen ed claims to cover all such changes and modifications.

What I claim as new and desire to secare by Letters Patent, is:

1. Process for the production of vitreous enamel compositions which comprises mixing together one or more oils, enamel frit, a coloring oxide, and a mineral grease or jelly such as petroleum jelly, to substantially a pasty consistency.

2. Process for the production of a vitreous enamel composition which comprises mixing a vegetab e oil such as oxidized linseed oil, a mineral oil such as parafiin oil, and ground enamel frit and mineral coloring matter to substantially a pasty consistency, by the use of a mineral grease or jelly such as petroleum jelly.

Process for the production of vitreous enamel compositions which comprises mixing one or more oils, enamel frit and a coloring oxide and working up the same with a mineral grease or jelly such as petroleum jelly.

4. A process for the production of vitreous enamel compositions for use in making vitreous enamel desi ns comprising Working up a vegetable oi such as oxidized linseed oil, a mineraloil such as parafiin oil,

and frit or quartz-like material and anya. fine mesh stencil, by means of a mineral grease or jelly such as petroleum jelly.

5. Process for the production of vitreous enamel compositions which com rises mixing oxidized linseed oil and para n oil with enamel frit and a mineral coloring matter and then workin up this mixture to la greasy substantially asty consistency by means of petroleum je ly.

6. A process for the production of vitreous enamel compositions for use in making vitreous enamel designs, comprising mixing oxidized linseed oil and paraflin oil in such proportion with enamel frit and mineral coloring matter as to produce a damp powder an working up the same to a greasy pasty consistency suited to transmission throu h a fine mesh stencil by adding petroleum elly.

7 Process for the production of vitreous enamel compositions which comprises making a liquid composition by mixin paraflin oil and linseed oil, mixing therewith ground enamel frit and mineral coloring matter to obtain a pasty consistency, and then working up the mass with a mineral grease or jelly.

8. Process for the production of vitreous enamel compositions which comprises making a liquid composition by mixing and heating parafiin oil, linseed oil and tallow, mixing therewith ground enamel frit and mineral coloring matter and then working up the mass to substantially a greasy pasty consistency by means of petroleum jelly.

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9. Process for the production of vitreous enamel com ositions which com rises mixing a vegeta 'le oil such as linsee oil, parafcoloring matter with an oily medium which pasty consistency comprising finely ground will liberate from the mixture that part of enamel frit, a coloring oxide, a vegetable oil in the paraflin oil which is held in suspension. such as linseed oil, a mineral oil such as 10. A vitreous enamel composition comparaffin oil and petroleum jelly. 5 prising finely ground enamel frit, a coloring In testimony whereof I have signed my oxide, vegetable and mineral oils and a minname to this specification. eral grease or jelly.

11. A vitreous enamel composition of a GEORGE McINTOSH SCOTT. 

